5A adjustable voltage regulator circuit 0-30 volts

hi guys today I will be making a simple and Powerful adjustable voltage regulator circuit which will provide output from 0 to 30 volts with up to 5 amperes output current you just require some few components like lm338 voltage regulator lm7812 voltage regulator 220 ohms resistor 10 kilo ohms resistor 5 kilo ohms potentiometer 2 pin terminal connectors 305 mm LED 3 pin header connector and 0.36 inch DC voltmeter I also prepared simple circuit diagram of the circuit in CAD as you can see here goes the DC input of 30 volts and 5 amperes clear LED with resistor for power indicator I used LM double three eight voltage regulator which provides maximum 5 amperes output and output voltage can be adjusted with this 5 kilo ohms potentiometer and here 220 ohms resistor for sensing output voltage I also use 12 volt regulator to power up the DC voltmeter so that output voltage can be monitored and controlled properly and here you get output from 0 to 30 volts at 5 amperes I clean the PCB with isopropyl alcohol and here our PCB is looking nice and clean I use normal sized heatsink for heat dissipation also used silicon pads for insulation for these both voltage regulators use screws with dust plastic bushes also called M3 washers it is used to fully isolate component from heatsink I simply place the PCB with components at their place and then soldered all the beans of both components also connected voltmeter in its connector and fixed it with double-sided tape at its place now our circuit is fully ready so let's prepare it for test connect output and input wires also add a potentiometer knob I powered the circuit with 24 volt 5 ampere smps and the output can be simply adjusted with this potentiometer I set the voltage at 12.4 Volts for testing the circuit also I use multimeter to monitor the amperes drawn by the load I used some small piece of nechrome wire for testing as you can see load even touched to above 5 amperes and there is about 1.2 to 1.3 volts voltage drop in the circuit which is quite acceptable you can also connected power LEDs and brightness can be controlled by decreasing or increasing voltage.